/*
 * Copyright 2013-2022 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package net.xmmpp.uc.im.broker.consumer;

import com.google.common.hash.HashCode;
import com.google.common.hash.HashFunction;
import com.google.common.hash.Hashing;
import org.apache.rocketmq.client.producer.MessageQueueSelector;
import org.apache.rocketmq.common.message.Message;
import org.apache.rocketmq.common.message.MessageQueue;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;

import java.nio.charset.StandardCharsets;
import java.util.List;

@Component
public class OrderlyMessageQueueSelector implements MessageQueueSelector {

	private static final Logger LOGGER = LoggerFactory.getLogger(OrderlyMessageQueueSelector.class);

	private static HashFunction hashFunction = Hashing.murmur3_128();

	/**
	 * to select a fixed queue by id.
	 * @param mqs all message queues of this topic.
	 * @param msg mq message.
	 * @param arg mq arguments.
	 * @return message queue selected.
	 */
	@Override
	public MessageQueue select(List<MessageQueue> mqs, Message msg, Object arg) {
		String uid = (String)arg;

		HashCode hashCode = hashFunction.hashString(uid, StandardCharsets.UTF_8);
		int index = hashCode.hashCode() % mqs.size();
		MessageQueue msgQueue = mqs.get(index);

		LOGGER.info("key -> " + arg + ", " + msgQueue + ", msg = " + new String(msg.getBody(), StandardCharsets.UTF_8));

		return msgQueue;
	}

}
